1. Field of the Invention
This invention relates generally to a slip casting mold for use in obtaining a cast article by casting a slip containing refractory powder such as ceramic powder, metal powder, or carbon powder and more particularly to a slip casting mold suitable for use in obtaining a cast article which requires a core having such complex shape that it can not be withdrawn because it has an inverse gradient.
2. Description of the Prior Art
When a hollow cast article whose hollow portion has complex shape, or a cast article which requires a core having such complex shape that it can not be withdrawn because of its inverse gradient, is cast by slip casting, it has been difficult or impossible to remove the core by the use of a conventional gypsum mold.
As one of the prior art techniques relating to the present invention, mention can be made of British Pat. No. 1,482,436. [METHOD FOR MAKING AN ARTICLE BY SLIP CASTING].
According to this prior art, a casting mold for a portion having complex shape is produced using an organic material which is soluble in a solvent, while a gypsum mold is used for a portion having simple shape. These two molds are then assembled to obtain a desired casting mold.
However, this method does not take into consideration the possibility that a density difference will occur on a green body between the organic portion and the gypsum portion depending upon the shape and size of the resulting cast article and will somehow affect the strength reliability, dimensional accuracy and workability.